Noncorrugating diaper



y 11, 1967 w. M. PITTENDREIGH ETAL 3,330,283

NONCORRUGATING DIAPER Filed Jan. 7, 1964 IN VENTORS ununm I I- PITTENDREIG 6 DRLE LL]. KERN United States Patent 3,330,283 NONCORRUGATING DIAPER William M. Pittendreigh, Greenville, and Dale W. Kern,

Ware Shoals, S.C., assignors to Riegel Textile Corporation, a corporation of Delaware Filed Jan. 7, 1964, Ser. No. 336,191 1 Claim. (Cl. 128-284) This invention relates to a diaper and more particularly to a diaper which will resist shrinking and corrugating when subjected to normal laundering practices.

The undesirable corrugations or puckering appear in woven diapers in the form of waves or ruts throughout the entire diaper as a result of shrinking caused by normal laundering practices.

In the normal finishing techniques of a diaper fabric woven from yarns spun of swellable stapel fibers, the fabric will shrink during the wet finishing thereof. Thereafter, the fabric will be framed or stretched in the dry finishing to restore the original dimensions of the fabric. This framing or stretching results in the formation of stresses and potential energy being imparted to the finished fabric which will leave the diaper with a potential desire to shrink or return to its previously shrunk dimensions.

Other factors which contribute to shrinking and therefore corrugating of the diaper fabric are the ends per inch of the warp yarns and the amount of twist or the twist multiplier of the filling yarns.

The ends per inch of the warp yarns control to some degree the amount of force or energy required to allow the filling yarns to contract or shrink since if the ends per inch of the warp yarns are increased, the fabric is denser and greater force or energy is required to allow the filling yarns to contract or shrink causing corrugations.

The twist imparted to the filling yarns also controls to some degree the amount of shrinkage. If a substantial amount of twist is imparted to the filling yarns, the potential energy set up in the finished fabric will be increased because there will be a greater tendency for these filing yarns to contract in the manner of a coil spring causing shrinking and corrugating.

Thereafter, during normal laundering, each fiber and each yarn, when thoroughly wetted, will swell and the potential energy imparted to the diaper during the weaving and finishing processes will be converted into kinetic energy. The swelling of these fibers and yarns within the diaper structure and the conversion of potential energy in the diaper to kinetic energy must be compensated for by a reorientation of the entire fabric structure. In a woven gauze diaper, this reorientation manifests itself by the component yarns assuming a more pronounced crimp and drawing themselves closer to one another thereby producing corrugations and shrinkage in the diaper.

It is therefore an object of this invention to provide improved methods to prevent undersirable corrugations and shrinkage in the diapers.

This invention provides novel weaving and finishing procedure which will effectively prevent the formation of corugations and reduce shrinkage in diapers following normal laundering. As discussed above it is the normal practice in textile finishing operations on fabrics of this type to allow the fabric web to shrink during wet finishing and then frame or stretch the fabric back to its original dimensions during dry finishing. In contrast, the novel procedure of this invention provides for allowing the fabric web to shrink during the normal wet finishing of the fabric. Following this the fabric is not stretched or framed back to the original dimensions, but only stretched or framed a small percent to allow the yarns to lie flat in a common plane throughout the diaper. This "ice elimination of most of framing or stretching in the finishing operation eliminates the building up of potential energy and stresses in the diaper which will cause corrugations and shrinkage in the diaper. Provision is made for the unrecovered shrinkage of the diaper fabric in calculating the finished dimensions of the diaper.

Also, during weaving this invention provided for increasing the ends per inch thereby providing a denser diaper fabric which requires more force or energy for the filling yarn to shrink which decreased the tendency toward shrinking in the finished diaper following laundering. The filling yarns were heavied to allow a reduction in the twist imparted thereto, which also reduced the tendency of the filling yarns to contract or shrink following laundering of the finished diaper.

This method of weaving and finishing a diaper provides the desirable prevention of the tendency of the fabric to corrugate and shrink following normal laundering.

Further features of this invention will be understood from the following description taken in conjunction with the accompanying drawings in which:

FIG. 1 is a perspective view of a diaper made in accordance with this invention;

FIG. 2 is a diagrammatic cross-sectional view of the diaper of this invention;

FIG. 3 is a perspective view of a diaper which has corrugated and shrunk; and

FIG. 4 is a diagrammatic cross-sectional View of a diaper which has corrugated and shrunk.

Referring to FIGS. 1 and 2, there is shown a diaper 10 made according to the novel processes of this invention. This diaper 10 has been allowed to shrink during the wet finishing and has been framed or stretched only a small percent to allow the yarns to lie fiat in a common plane. This diaper 10 when subjected to normal laundering practices did not shrink or corrugate because less stresses or potential energy were set up during the weaving and finishing operations for the reasons set out above. This diaper 10 contains warp yarns 11 and filling yarns 12 which lie fiat in a common plane following laundering, as may be seen in FIGS. 1 and 2.

This diaper 10 was woven approximately 42% inches in width and finished approximately 40 inches in width as opposed to the normal griege width of 40%. inches to finish 40 inches in width, since the novel finishing procedures of this invention did not frame or stretch the diaper fabric back to its original griege width.

In the weaving of the diaper 10, the size of the filling yarns 12 was heavied from 29s to 22s to allow a reduction in the twist multiplier from the normal of 4.15 to the lower twist multiplier of no higher than 3.75 to reduce the tendency of these filling yarns 12 to contract or shrink following laundering of the diaper 10 due to the amount of twist imparted to these yarns 12. Also, the ends per inch of the warp yarns 11 were increased from 78 to not less than to provide a denser diaper 10 which would require more force or energy to shrink and therefore corrugate in the filling direction.

In contrast, FIGS. 3 and 4 illustrate a diaper 13 which has not been made according to the novel processes of this invention. This diaper 13 was woven and finished according to the conventional practices of weaving the fabric with the conventional ends per inch for the warp yarns and the conventional twist multiplier for the filling yarns and thereafter allowing the fabric to shrink during the wet finishing and then stretching or framing the fabric back to its origin-a1 dimensions, which allowed stresses and potential energy to set up in the diaper. When this diaper 13 was laundered, the filling yarns 14 and warp yarns 15 reoriented themselves, for the reasons set out above, to

cause undesirable shrinkage and produce corrugations 16, as may be seen in FIGS. 3 and 4.

This invention has thus provided a diaper and method of making same which will efiectively prevent undesirable shrinkage and corrugating without incurring additional expensive manufacturing steps.

This invention has been described in detail above for purposes of illustration only and is not intended to be limited by this description or otherwise, except as defined in the appended claim.

What is claimed is:

A method of making a diaper which will resist shrinking and corrugating comprising the steps of:

(a) weaving said diaper with at least 90 ends per inch for the warp and with a twist multiplier of no higher 7 than 3.75 for the filling;

(b) subjecting said diaper to normal chemical finishing processes which will allow normal shrinking of said diaper; and

(c) stretching the yarns of said diaper which have been shrunk only a small amount necessary to straighten the yarns but not enough to return said diaper to the original woven dimensions thereof before shrinking.

References Cited UNITED STATES PATENTS 2,945,738 7/1960 Harmon 128-284 X 2,977,997 4/1961 Seltzer l28-284 X 10 2,991,786 7/1961 Sullivan 128284 FOREIGN PATENTS 14,453 9/1933 Australia.

15 RICHARD A. GAUDET, Primary Examiner.

LAWRENCE W. TRAPP, Examiner. 

